The move gave Kasparov a 1-0 lead in the series, the second between the two Soviet grandmasters for the world championship.

Their first match was halted in February by the head of the World Chess Federation, who said both players had become exhausted.

Nimzo-Indian Defense

When the two players adjourned Tuesday night on Kasparov's sealed 42nd move, some grandmasters predicted that Kasparov had a good chance of winning. He was playing white.

The contest began with the Romanishin variation of the Nimzo-Indian defense. But the 22-year-old Kasparov introduced some changes that left Karpov, 33, at a disadvantage and unable to develop the pieces on the queen's side of the board.

This is the first time Kasparov has had the lead in the prolonged title series. The last round of games ended with Karpov leading 5-3 after Kasparov narrowed the champion's original 5-0 lead. Six victories were needed to win that series.

The current round is limited to 24 games. The first player to win six games or accumulate 12 1/2 points is the victor. A win counts one point, a draw a half-point.

If the players are tied at the end of 24 games, Karpov will retain his title.